Product description: Color: 2 pieces blue Material: stainless steel and ABS plastic Product size: 2.84 x 2.84 x 1.87 inches / 7.2 x 7.2 x 5 cm Package includes: 2 x Pet Training Bells Description: Effective potty training --- apprentice to ring a bell to go outside or use the bathroom instead of scratching and barking at the door to get your attention, the button on top is flat and wide what a Dog is easy or cat to push it, set of two bells can be placed outside or inside the door. Non-slip rubber bottom --- There are 3 rubber feet under the bottom helping to hold the bell in place. It won't slide easily on the floor and also can protect the floor from scratches. For small dogs and cats --- This towel-sized pet trainer is 7.2 cm (2.24 inch) in diameter, and the bell is made of stainless steel, ABS plastic and has a cute paw print. Clear Ring --- Since the pet is not hanging on the door, it can press the bell with its paws to make the volume louder and avoid the ringing signal. How to Train Your Pet --- STEP 1: Put the doorbells on the doorknob. STEP 2: When your dog needs to go out, take her to the doorbells and ring the bells with her paw and give your dog an order, then open the door to let her out. STEP 3: Repeat the process over and over if your dog has to walk for three weeks or less, always with the same command and praise. Then your dog will remember this way.